Aquatic Plant Surveys

Three Lakes Council started doing systematic plant surveys in 2008, and that year we found a new invasive plant and took action. That is a whole separate story.  The result has convinced us of the effectiveness of having professionals perform a regular lake-wide survey.  We repeated the survey on Waccabuc annually as part of our ongoing monitoring for Brazilan Elodea.  In 2016, we resurveyed Oscaleta and Rippowam to check for new invasives, and also to give some perspective on the relative plant densities over the years.  We also continued our monitoring on Waccabuc. To reduce expense, we plan to alternate surveys going forward – one year Waccabuc, and the next year Oscaleta and Rippowam.

Waccabuc Aquatic Plant Survey – 2016
This survey confirmed that the invasive plant, Brazilian elodea, was not seen in the lake. This marks the 6th year since it was seen. The plant community is generally stable, although for the second year bassweed was more robust. No new invasives were discovered.

Oscaleta Aquatic Plant Survey – 2016
This survey identified some new plants in Lake Oscaleta that were not identified by the same company in 2008, although they had been seen in our 2011 survey.  The good news is that no new invasives were discovered. The advantage of having the same organization perform the survey using the same techniques is that we can compare results from 2008 with those from 2016.

Rippowam Aquatic Plant Survey – 2016
More types of plants were found in Rippowam in 2016 than in 2008, although again these were spotted in the 2011 survey, and no new invasives. The report includes comparisons between 2008 and 2016.

Older and different surveys

Waccabuc Aquatic Plant Survey – 2015
Another plant survey of Lake Waccabuc in 2015 showed no Brazilian elodea – the fifth year, and a milestone. The survey by ABI / SOL (a change of ownership occurred) also showed very robust plant growth in 2015, and less filamentous algae, a finding that many lake users echoed. Plant diversity appeared to increase in 2015.

Waccabuc Aquatic Plant Survey – 2014
The primary goal remained to search for Brazilian elodea, the invasive plant that we removed from the north cove. None was found. So far so good!

Unfortunately, the survey found 5 water chestnut plants among the water lilies near the south shore.  This is an invasive plant which covers significant portions of the Hudson River.  It’s also found nearby in Mountain Lakes Park.  This reinforces the need to be vigilant for water chestnut – and other new invasives.

Waccabuc Aquatic Plant Survey – 2013
Once again, 3LC hired ABI to repeat their rake toss survey, primarily to search for the invasive Brazilian elodea.  No Brazilian elodea was found during the July 24, 2013 survey. Hooray! Three years without Brazilian elodea can give us some confidence that we may have eradicated this plant – but we need to remain vigilant. Click the title for the report.

Waccabuc Aquatic Plant Survey – 2012
A rake toss plant survey of Lake Waccabuc  was completed on July 19, 2012.  The primary goal was to continue to monitor for the invasive plant, Brazilian elodea (Egeria densa), and to gather data to allow us to evaluate the trends in plant growth on the lakes.  No Brazilan elodea was found in 2012.  The report shows that some new native plants were collected (watermeal, duckweed, and watermoss), but they are not new to our lakes.   Click the header for the report.

Waccabuc Shoreline Survey – 2012
Robynn Shannon performed a shoreline survey and submitted herbarium specimens for the plants found on Lake Waccabuc.  The report documents the presence of a rare plant, Potamogeton diversifolius, in Lake Waccabuc.  This is the first time this plant has been found in Westchester County.

Oscaleta – Rippowam Aquatic Plant and Shoreline Survey – 2011
In 2011, Robynn Shannon surveyed the plants on the shoreline and in lakes Oscaleta and Rippowam.  A primary concern was to monitor for invasive species, and also to begin to document shoreline plants.  Herbarium specimens were collected and submitted for nearly all of the species. Robynn found interesting white water lily morphologies on Lake Oscaleta that may result in further study.

Waccabuc Aquatic Plant Survey – 2011
ABI returned to Lake Waccabuc on July 20 and 21 to repeat the aquatic plant survey and look for Brazilian elodea.  They did not find the invasive plant, a good sign after continued efforts to remove that plant.

Waccabuc Aquatic Plant Survey – 2010
ABI performed an aquatic plant survey of Lake Waccabuc on August 23, 2010.  The primary reason for the survey was to look for Brazilian elodea (BE), aka Egeria densa.  BE was not found where it had been harvested by suction harvesters and hand harvesting, but it was found in one location off the island.  The report also states that floating and submersed plants were generally less dense in 2010 than they had been in 2008.  Brittle naiad, an invasive plant found in Oscaleta in 2008, was found in Waccabuc in 2010.

Aquatic Plant Survey – 2008
The Three Lakes Council hired Allied Biological, Inc. to do an aquatic plant survey of the Three Lakes.  Chris Doyle, our lake manager, and an assistant visited the lakes in August, 2008.  The full report  (5.2M) from the survey reviews the procedure, the plants found on the Three Lakes, a summary of the findings for each lake, and some management recommendations.

Chris Doyle of ABI gave a presentation on May 15, 2009 at the Three Lakes Council seminar, Aquatic Plants of the Three Lakes.  This was also filmed for Lewisboro Cable TV, so if you’d like to see a DVD, contact us.

Aquatic Plants in the 1980’s
Ken Soltesz compiled a list of aquatic plants in the lakes in the 1980’s.

Aquatic Plants in 1970
Robert L Johnson of Cornell issued a report on the Aquatic Plants of the Three Lakes in 1970.  It was notable that Eurasian water milfoil, a new invasive, was found only in one spot by a boat launch in Lake Oscaleta. EWM is now the plant that is most dense and found most frequently on all three lakes.